You know what? I think that's great! It's installing 3rd-party keyboards, but with security. I don't want any 3rd-party keyboard taking a record of my password. Yes, Swype or Fleksy could be very trustworthy for many people, but I'm sure their security procedures aren't close to Apple's, and I don't know if their keyboards have some security flaws or not.
While you may know the consequences of using a 3rd-party keyboard, the millions and millions of iPhone users don't, but people have requested a lot for it. Apple has responded and enabled 3rd-party keyboards, but they don't want to put people's vulnerable information at risk.
I like how Apple cares somewhat about people's security, unlike some of its competitors. They're opening up iOS 8, but with a guard